Clinical Trial Update

Oxford, UK - 3 June 2013: Oxford BioMedica ("Oxford BioMedica" or "the Company") (LSE: OXB), the leading gene-based biopharmaceutical company, today announces that it has voluntarily paused recruitment into the RetinoStat® Phase I, StarGen™ Phase I/IIa and UshStat® Phase I/IIa studies, as a precautionary measure, whilst the Company investigates the recent detection of very low concentrations of potential impurities derived from a widely-used third party raw material.

A new, highly sensitive test method has recently been introduced into the Company's wide range of analytical methods and quality assurance processes used for routine batch testing. Using this method, potential impurities have been detected at very low concentrations in clinical trial material. No safety concerns relating to any of the aforementioned products have been identified in any pre-clinical and clinical data generated to date and there is no reason to believe that the favourable safety profile of these products will be affected.

Such precautionary measures are routine and Oxford BioMedica is working very closely with the regulatory authorities to complete its investigations. The Company is committed to resuming the clinical trials as soon as possible and will continue to keep the market informed as appropriate.

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For further information, please contact:

Oxford BioMedica plc:

Lara Mott, Head of Corporate Communications

Tel: +44 (0)1865 783 000

Media Enquiries:

Mary-Jane Elliott/Claire Dickinson

M:Communications

Tel: +44 (0)20 7920 2360

Notes to editors

1. Oxford BioMedica®

Oxford BioMedica plc (LSE: OXB) is a biopharmaceutical company developing innovative gene-based medicines and therapeutic vaccines that aim to improve the lives of patients with high unmet medical needs. The Company's technology platform includes a highly efficient LentiVector® gene delivery system, which has specific advantages for targeting diseases of the central nervous system and the eye; and a unique tumour antigen (5T4), which is an ideal target for anti-cancer therapy. Through in-house and collaborative research, Oxford BioMedica has a broad pipeline with current partners and licensees including Sanofi, Pfizer, Novartis, GlaxoSmithKline, MolMed, Sigma-Aldrich, Biogen Idec, Emergent BioSolutions, ImaginAb and Immune Design Corp. Further information is available at www.oxfordbiomedica.co.uk and www.oxbsolutions.co.uk.